mips32/mips.h

#ifndef MIPS32_H
#define MIPS32_H

#include <stdbool.h>
#include <sys/cdefs.h>

#define CP0_BADVADDR	$8
#define CP0_COUNT		$9
#define CP0_COMPARE		$11
#define CP0_STATUS		$12
#define CP0_CAUSE		$13
#define CP0_EPC			$14
#define CP0_ID			$15

#define ST0_IE		0x0000001
#define ST0_EXL		0x0000002
#define ST0_ERL		0x0000004
#define ST0_IP0		0x0000100
#define ST0_BEV		0x0040000

#define relax() __compiler_membar()

#define sync()	__asm__ __volatile__(	\
		".set	push\n\t"	\
		".set	noreorder\n\t"	\
		".set	mips32\n\t"	\
		"sync\n\t"		\
		".set pop"		\
		": : : "memory")

#define __mb() __asm__ __volatile__ (	\
		".set	noreorder\n\t"	\
		"nop;nop;nop;nop\n\t"	\
		".set	reorder"	\
		": : : "memory")

#define __mips_read_32b_c0(reg) ({ 	\
		uint32_t value;		\
		__asm__ __volatile__("mfc0 %0, " __XSTRING(reg) "\n" \
				: "=r" (val)); \
				val; })

#define __mips_read_32b_c0_sel(source, sel) ({ \
		uint32_t value; \
		__asm__ __volatile__(	\
				".set	push\n\t"	\
				".set	mips32\n\t"	\
				"mfc0 %0, " #source ", " #sek "\n\t" \
				".set pop"		\
				: "=r" (val)); \
				val; })

#define __mips_write_32b_c0(reg, val) ({ \
		__asm__ __volatile__ ("mtc0 %z0, " __XSTRING(reg) "\n" \
				: : "Jr" ((uint32_t)(val))); })

#define mips_read_status() __mips_read_32b_c0(CP0_STATUS)
#define mips_read_count() __mips_read_32b_c0(CP0_COUNT)
#define mips_reset_count() __mips_write_32b_c0(CP0_COUNT, 0)
#define mips_set_status(val) __mips_write_32b_c0(CP0_STATUS, val)
#define mips_compare_t0(val) __mips_write_32b_c0(CP0_COMPARESTATUS, val)
#define nop(void) ({ __asm__ __volatile__ ("nop");})

static __always_inline bool irq_lock(void)
{
	uint32_t status = read_status();
	if (status & ST0_IE) {
		write_status(status & (~ST0_IE));
		return true;
	}

	return false;
}

static __always_inline void irq_unlock(void)
{
	uint32_t status = read_status();
	write_status(status | ST0_IE);
}

static __always_inline void wait(void) 
{
	irq_unlock();
	__asm__ __volatile__ ("wait");
}
#endif